1. Field of the Invention
The increasing ease of cloning and synthesizing DNA sequences has greatly expanded opportunities for detecting particular nucleic acid sequences of interest. No longer must one rely on the use of immunocomplexes for the detection of pathogens, lesions, antigens, and the like. Rather than detecting particular determinant sites, one can detect DNA sequences or RNA sequences associated with a particular cell. In this manner, diseases can be diagnosed, phenotypes and genotypes can be analyzed, as well as polymorphisms, relationships between cells, and the like.
For the most part, analyses of DNA sequences have involved the binding of a sequence to a solid support and hybridization of a complementary sequence to the bound sequence. The annealing and complexing step usually involves an extended period of time and requires careful washing to minimize non-specific background signals. There is substantial interest in developing new techniques for analyzing nucleic acid sequences, which are more rapid, minimize the number of manipulative steps, and provide for an increased signal to noise ratio.
2. Description of Relevant Literature
Meinkoth and Wahl, Anal. Biochem., (1984) 138:267-284, provide a review article of hybridization techniques. See also Leary et al., Proc. Natl. Acad. Sci. USA (1983) 80:4045-4049, for a description of the dot-blot assay. Sandwich hybridization is described by Ranki et al., Curr. Top. Microbiol. Immunology (1983) pp. 308ff. See also Ranki et al., Gene (1983) 21:77-85, Virtanen et al., Lancet (1983) 381-383, and U.S. Pat. No. 4,486,539. EPA 123,300 describes biotin-avidin complexes for use in detecting nucleic acid sequences.